trp decarboxylation with HCl/benzene?

[hypo]

but the water is added after the CuO is filtered of and the CO2
has gone away, isn't it?

[hypo]

it just takes longer (about 1h-1.5h). same result as with DMSO.

the reason i put works in quotes is that for some reason on
extracting with EtOAc everything turns into tar.

basifying with Na2CO3, no basifying, extraction of the organic
phase with 0.5N H2SO4 has all been tried.

(sidenote: boiling the tar in toluene and cooling gives a green
precipitate)

plan for next week: wash with EDTA solution, try the charcoal / celite
trick and if this doesn't help file this method under "workup impossible
probably due to bad lab technique".  

[hypo]

(first of all, the 2 articles were retrieved by lugh (thaaanks )
and the chemists use the known diphenyl methane under N2 method.)

but rhodium (or other chem god): do you know how this reaction
is supposed to work? this time, i really gave some thought to it,
but i just don't get it!? i have no doubt that it does work (what
would the yellow precipitate on hydrolysis be?), i just can't understand how!

even without trying to come up with electron dances:

1) in the picture you posted, it's clear that the covalent O-Cu bond is
in reality an ionic bond, where the oxygen has a negative charge.

2) the CO2 evolution and the red inorganic precipitate happen in
aprotic medium.

CO2 is a neutral molecule, so where the heck does the negative
charge go? my first thought was that the red precipitate is copper
(CuO is black according to merck and where should the oxygen come
from?) and that the negative charge would reduce the ionic copper
to metalic copper, but that would leave us with a tryptamine radical!
i can't believe this. the other idea i had was that one ends up with
an organo copper compound. but what would then the red precipitate be?
and it sounds totally strange too.

so please, what am i missing?

[hypo]

one theory i have (seeing the low yield), is that
the reaction gives partly the copper salt of the
tryptamine derivate which misses one proton on the
-NH2 group. (an amide?) and partly polimerised crap,
which happens when the copper is reduced (thus the
red precipitate).

but that sounds very unlikely too...